Event-triggered sub-optimal control for two-time-scale systems with unknown dynamics

The paper investigates the event-triggered sub-optimal control problem for two-time-scale systems with unknown slow dynamics. Specifically, a composite event-triggered optimal controller design is proposed for the decoupled slow and fast subsystems with different triggering conditions. To handle the unknown dynamics, the actor and critic networks are utilized to approximate the optimal controller employing tuning laws applied to the weights. The results indicate that a system employing the proposed event-triggered mechanism can achieve asymptotic stability and afford a sub-optimal controller. Furthermore, Zeno behavior is excluded with rigorous proof, and several simulation examples and comparative studies demonstrate the method's effectiveness.